(Adapted from the application) The core laboratory provides chemical synthesis, purification, and analysis services to each of the projects. By centralizing these activities, the project will make more efficient use of its resources and insure high quality and consistency in the starting materials for each section. Specifically, the core will synthesize wild type amyloid beta-proteins, truncated and elongated forms, as well as derivatives containing amino acid substitutions, D-isomers, unusual amino acids, and radioactive and stable atomic isomers. Peptide and non-peptide inhibitors of fibrillogenesis will be prepared. Cleaved and deprotected peptides will be purified (greater than 95%+) by HPLC to ensure homogeneous starting material. Chemical and isotopic purity will be confirmed by analytical HPLC, amino acid analysis, protein sequencing, and mass spectrometry. Proteins produced in in vitro expression systems will be purified and characterized by similar means.